Instruments for screwing or driving screws into bone material are known. The screws are typically presented to the surgeon in a tray, wherein the heads of the screw are exposed. To maintain a sterile environment, the heads of the screw are configured to engage the instrument. Accordingly, the surgeon stabs the head of the screw with an end of the instrument to engage the screw head in a temporary setting, and then must secure the head to the instrument. Current instruments require two hands to perform such an act. One hand is used to engage the head in a temporary setting. However a second hand is needed to secure the head of the screw to the instrument. Specifically, one hand supports the driver while the other hand rotates a sleeve in a labor intensive action to threadedly engage the screw head to the end of the instrument. Accordingly it remains desirable to have an instrument which requires the use of a single hand to engage the head of a screw. It further remains desirable to have an instrument which engages the head of the screw in a single motion.